First lady Michelle Obama and her daughters Malia, center, and Sasha watch a Peking opera performance along with a group of American schoolchildren who are visiting China.

BEIJING — U.S. first lady Michelle Obama told students in China, which has some of the world’s tightest restrictions on the Internet, that freedom of speech and unfettered access to information make countries stronger and should be universal rights.

Mrs. Obama was speaking Saturday at Peking University in Beijing during a weeklong trip aimed at promoting educational exchanges between the U.S. and China. The trip also took on political overtones when she was granted a previously unscheduled meeting with Chinese President Xi Jinping on Friday.

Mrs. Obama said the free flow of information is crucial “because that’s how we discover truth, that’s how we learn what’s really happening in our communities and our country and our world.”

“And that’s how we decide which values and ideas we think are best — by questioning and debating them vigorously, by listening to all sides of every argument and by judging for ourselves,” she said.

China blocks many foreign news sites and social media services such as Facebook, Twitter and YouTube. Its army of censors routinely filters out information deemed offensive by the government and silences dissenting voices.

Though not likely to be well-received by the government, Mrs. Obama’s remarks may not draw any strong protest because her speech and a subsequent moderated discussion among 50 students — sitting in two identical conference rooms in Beijing and Palo Alto, Calif., but connected via modern technology — focused mainly on the value of educational exchanges.

Fulbright scholar Eleanor Goodman from Harvard University’s Fairbanks Center for East Asian Research said the first lady probably “felt a need to make that statement.”

“It was firm but not overbearing,” Goodman said.

Sunny Ni, a Chinese student studying environmentalism at the State University of New York College of Environmental Science and Forestry, said that she has no problem accessing information for her studies, and that China is improving with free flow of information.

“It’s a step-by-step process,” Ni said.

Ni said Mrs. Obama impressed her by saying studying abroad should not be the privilege of the wealthy.

In her speech, the first lady said that the U.S. government is supporting more American students in China than in any other country, and that her husband has launched an initiative to send more American students with diverse backgrounds to China.

“Our hope is to build connections between people of all races and socio-economic backgrounds, because it is that diversity that truly will change the face of our relationships,” Mrs. Obama said.

Ni said Mrs. Obama also appealed to her by saying people need to connect with each other to take on global challenges.

Mrs. Obama’s meeting Friday with Xi, though not unexpected, was not originally part of the itinerary for her seven-day, three-city trip to China, and was a sign that the leaders of the world’s two largest economies are seeking to build stronger personal bonds.

Xi said he cherished the “personal friendship” he has established with President Barack Obama, and Mrs. Obama thanked him for his hospitality.

Teng Jianqun, director of the American studies department at government-administered think tank China Institute of International Studies, said that Mrs. Obama also likely served as a messenger on behalf of the U.S. president.

The trip, the first time a U.S. president’s wife has independently visited China, also has given her an opportunity to engage with Xi’s wife, Peng Liyuan, who watched Mrs. Obama attempt some Chinese calligraphy Friday while offering words of encouragement. Peng wrote in calligraphy a Chinese aphorism on virtues and presented it as a personal gift to Mrs. Obama.

Peng, a popular singer, has broken the mold of reticent Chinese first ladies. She was better known than her husband before Xi was named Communist Party leader and president, and has used her celebrity to promote AIDS awareness and other causes as China seeks to soften its international image.

Peng is widely admired at home, and some Chinese grumbled when Mrs. Obama stayed in Washington last June while Peng accompanied her husband on a visit to California for a no-tie session with President Obama.

Mrs. Obama’s good-will trip to China has allowed her to make up for that absence and to bond personally with Peng in what is dubbed as “first-lady diplomacy,” although the get-together of two highly popular figures whose husbands are leading the world’s two largest economies has lent itself to comparison and a bit of rivalry.

Chinese news websites — prior to Mrs. Obama’s visit — declared a victory for Peng in style, but a U.S. fashion editor told The Washington Post that Mrs. Obama was the clear winner. Pamela Edwards Christiani, the style and beauty director of Essence magazine, also noted that Mrs. Obama enjoys an advantage in height.

The difference in height apparently was narrowed Friday when Mrs. Obama opted for flats and low heels while her host chose high-heels. Peng appeared decorous, if not a bit too stiff, while Mrs. Obama looked more relaxed as they walked through the grounds of the former Imperial Palace. Peng later hosted a private dinner for Mrs. Obama, and Xi did not attend.

Mrs. Obama, who is traveling with her two daughters and her mother, will visit the Great Wall outside Beijing on Sunday, and is due to fly Monday to Xi’an, home to the famed Terra Cotta Warriors Museum. She also will visit a panda breeding facility outside Chengdu in the southwest before she departs for the United States on Wednesday.